1. Field of the Invention
The present invention relates to an automatic original supplying apparatus in which upper separation and lower separation can be performed selectively, and more particularly, it relates to an automatic sheet supplying apparatus used in an original processing apparatus for successively supplying originals to an image forming apparatus having both a facsimile function and an original copying function, and an image forming apparatus for forming an image on a sheet supplied by the automatic sheet supplying apparatus.
2. Related Background Art
In the past, a page sequence for processing an original bundle was different between in a facsimile mode and an original copying mode. That is to say, in the facsimile mode, the originals were successively supplied from a first page so that a receiver can read the originals from the first page, and, in the copying mode, the originals were successively copied from a last page so that the copies are stacked in the same page sequence as that of the originals.
However, recently, composite machines of digital type including a facsimile function and a copying function has been developed. In such composite machines, either of the following arrangements was required for processing originals and for effecting first page supply in a facsimile mode and last page supply in a copying mode.
First of all, as a first arrangement, there is a system as shown in FIG. 15, which will be described hereinbelow. In FIG. 15, an upper block indicated by the two-dot and chain line schematically shows a conventional original processing apparatus, and a lower block indicated by the two-dot and chain line schematically shows a composite image forming apparatus of digital type (including a facsimile function and a copying function). In this system, in order to avoid operator's handling trouble, originals are stacked with imaged surfaces thereof facing upside (referred to as "face-up" hereinafter) both in a facsimile mode and in a copy mode so that the originals to be read are successively supplied to the image forming apparatus from a last page. In the copy mode, the originals are successively copied in the reverse page sequence (i.e. from the last page), and in the facsimile mode, after information regarding all pages is stored in a memory temporarily, the information is successively transmitted from a first page. Now, such operation will be explained with reference to FIG. 15.
First of all, the originals D.sub.1 to be processed are stacked on an original tray 201 in the face-up fashion both in the facsimile mode and in the copy mode. The original bundle D.sub.1 is urged against a pick-up roller 215 by a weight roller 202, so that the originals are supplied one by one from a lowermost one by means of the pick-up roller. A pre-separation plate 216 serves to prevent the double-feed of originals. A pair of rollers (comprised of a feed roller 204 and a retard roller 203 to which a driving force can be transmitted through a torque limiter (not shown)) serve to separate and convey the originals one by one in a retard fashion. A pair of regist rollers 205a, 205b serve to convey the original onto an original glass platen 209 in a timed relation. An original convey belt 208 is supported by a belt drive roller 207 and an idler roller 206 so that the belt is rotated in a direction shown by the arrow. The original convey belt 208 serves to temporarily stop the original at a predetermined position on the original glass platen 209. At this point, a scanner unit 210 comprising a halogen lamp 210a, a reflection bond 210b and a reflection mirror 210c is shifted to expose the original; meanwhile image information on the original is read by an arrow of CCD sensors 210 arranged side by side across a maximum width of the original.
In the facsimile mode, after the read information is temporarily stored in a memory 230, the information is rearranged from the first page to the last page, and the rearranged information is transmitted. In the copy mode, the read information is directly sent to a laser driver 240 without through the memory, and latent images are successively formed on a photosensitive drum (not shown) in the reverse page sequence.
The originals which were read are successively discharged and stacked on an original discharge tray 212 by the original convey belt 208 and a convey roller 211.
Other than the above-mentioned arrangement, there may be provided an original tray for the facsimile mode and an original tray for the copy mode so that the originals stacked on the facsimile tray are successively supplied from an uppermost one and the originals stacked on the copy tray are successively supplied from a lowermost one.
However, regarding the above-mentioned conventional cases, in case of the first arrangement (in the facsimile mode, after all information is temporarily stored in the memory, the information is transmitted from the first page), an expensive and large capacity memory is required, and the transmission cannot be performed immediately after of the reading of the original to cause the great time lag.
In case of the second arrangement (provision of facsimile tray and copy tray), two separation and convey means are required, thereby making the entire system complicated, bulky and expensive.